A checklist of lichens known from the Philippines

Lichens are formed by the symbiotic partnership between fungi and photoautotrophic algae or cyanobacteria. Lichen species are found all over the world and may grow under diverse and extreme environments and may colonize substrates such as rocks, bark or woody plants, leaves of vascular plants, soil, mosses and other lichen thalli including artificial substrates such as concrete, glass, metals, and plastics. Despite the high diversity of lichens in the tropics, very little information is known about them particularly in the Philippines. So far, the most comprehensive listing of lichens for the country was done by Gruezo in the 70's when he reported 1,108 published taxa distributed in 137 genera, 789 species, 3 subspecies, 153 varieties, 28 formae, and 1 subforma. In recent years, lichenology in the Philippines has progressed beyond species list to diversity, bioactivity, and biomonitoring. Several papers have documented the occurrence and distribution of lichen species from various parts of the Philippines including the Cordillera and Ilocos regions, Bataan, Calabarzon, Pangasinan, Nueva Vizcaya, Negros Occidental, Bukidnon, and Palawan. This paper presents an update on the lichen checklist for the Philippines based on publications in the 40 years following Gruezo's publication in 1979. These studies updated the list of species of lichens in the Philippines to 1,262 published taxa with 1,234 validated species names distributed into 65 families, 229 genera, 10 subspecies, 92 varieties, 15 formae, and 1 subforma.